We are installing a 10ton Carrier heat pump split unit system.(R410A) The compressor located on the 8th floor and the fan coil located on the ground floor. Is this require to have liquid solenoid valve?

Also, for the above system the liquid line 1/2 suction line 1 1/8. The install guy use 5/8 for the liquid line and 1 3/8 for the suction. What kind of problem we will face with the over size piping and how can we correct the problem if we can't replace the piping?

Thanks.

10-31-2012, 11:34 AM

dandyme

1-what does install manual indicate pertaining to LLS?

2-got a model #

10-31-2012, 11:14 PM

heatingman

The piping is likely not oversized for the application you have likely over a 100 ft lineset.

With the compressor on the roof, the biggest issue will be oil return. Is this r22 or 410a. If 410a, the oil return will be less troublesome due to POE oils ability to mix with vapor refrigerant. If R22, then you will need a suction line trap at the base of the riser, and every 20 ft of vertical rise, and an inverted trap at the very top of the riser. The LL solenoid is a good idea to aid in the prevention of refrigerant migration.

But, check with the OEM, and request a long lineset application supplement.

11-01-2012, 01:54 AM

manny238

Your best bet would be to contact Carrier tech support or read the installation manual. Like heatingman said a LL valve would be a good idea

11-01-2012, 05:59 AM

beenthere

The liquid line will hold 4 plus extra pounds of charge. The vapor line will hold almost an extra pound of charge. Suction velocity will be border line at only 1344FPM, which is ok. A solenoid to help prevent migration would be a good accessory.